Quote classy player="classy player"number on shirts should be names or position numbers ie 1full back.2wing.3centre and so on much easier that way,what position is 23 or 19.'"
As Fred pointed out times have moved, and so do the players, often see number 1 – full back, play at scrum half, or loose forward at an attacking scrum.
Quote classy player="Starbug"Remember Darren Abrams decision to number the players by alphabetical order to remove any perception they were part of a 1 st team and the ones outside the 17 were replacements, a correct decision IMO'"
Disagree,

have the balls to pick your best team 1 – 17, those in the 17 need to fight to remain in the team knowing full well those outside the 17 are fighting for their place.
Quote classy player="Leyther_Matt"I much prefer squad numbers. Dead easy to consult a list of numbers to identify an opposition player as who in the crowd has an accurate team list for 1-17 that day?!'"

Agreed, I prefer squad numbers,